Means for twisting yarn



Jan. 11, 1938. J. O'DOWD 2,104,810

- MEANS FOR TWISTING YARN Filed April 24, 1955 INVENTOR Leslie J. O Dowd 5 dergoing the Patented Jan. 11, 1938 UNITED STATES MEANS FOR TWISTlNG YARN Leslie J. ODowd, Drummondville, Quebec, Canada, assignor to Celanese Corporation of America, a corporation oi. Delaware Application April 24,

4 Claims.

This invention relates to the method of and means for twisting yarns or threads and relates more particularlyto the production of yarns. or threads of high twist and of relatively fine denier 5 or of low tenacity by means of a fiyer or analogous twisting device.

An object. of the invention is to twist yarns in a very economical and efficient manner to give an optimum uniform effect in the fabric made from the twisted yarns. Another object of my invention is to provide means for employing a fiyer twisting device to impart high twist to yarns of fine denier and/or low tenacity. A still further object of my invention is to provide means for employing a fiyer twisting device to impart twist to yarns wherein an even tension is applied to the yarn during the twisting regardless of the depth of yarn on the supply bobbin. Other objects of my invention will appear from the following detailed description.

In the drawing wherein like reference numer-' by means of a fiyer twister, it was found that the yarns tend to break or be damaged. This causes so many interruptions in the operations and necessitates so much supervision that the twisting operation by means of a fiyer cannot be carried out with complete commercial success. found that this'iis due to the fact that in previous apparatus for fiyer twisting a maximum and uniform amountof tension-could not be'applied by the ordinary type of stationary guide eyes for guiding the yarn leaving the fiyer and travelling toward the take-up device. It was seen that there was need of some kind of tension regulator arising from the fact that, when twisting with .the use of the ordinary fiyer, great variations in tension occurred in the thread while it was unactual process of twisting. It was observed that in accordance with recognized principles, the tension on the twisting yarn increases considerably as the supply bobbin empties. It was also found that when, in the course 55 of twisting, the thread was drawn from the I have 1935, Serial No. 17,943

top of the bobbin, the tension is lighter than when it is being drawn from the bottom of the bobbin. These causes, taken together, result in a very great difference in tension, so that in the ordinary course of twisting the highest tension 5 normally obtained may be two or three times as high as the lowest tension and even greater extremes than this are possible.

It was found in the twisting practice that the tension on the thread or yarn between the fiyer 10 and the take-up bobbin, that is, at that part of the yarn where the twist is actually being inserted, afiected considerably the characteristics of the resulting yarn, for instance, its crepeing property. Thus,- in respect tothis crepeing prop- 15 erty, if the tension is too light, the thread generally will not crepe so highly, but if the tension is sufliciently heavy the maximum crepe may be obtained. As a rule, it was found best to use a tension as heavy as the yarn will bear without breaking more than is customary during the twisting process. It was further, found that the amount of tension employed at that part of the yarn where twist is being actually inserted considerably affected the characteristic of the yarn in respect to its compactness For instance, the higher the tension, the more compact and uniform will be the diameter of the yarn, while if the tension is low, the filaments are not compacted tightly together although there may be inserted in the yarn the same number of turns per inch. This looseness of filaments gives rise to a spiral effect in the yarn. Y

By employing this invention, that is, by automatically regulating the tension of the thread, especially at that place where the twist actually is being inserted into the thread, it is possible to twist with the maximum desirable tension on everythread being twisted and to keep this tension approximately constant throughout the course of the twisting operation on every bobbin or unit of the device. The result of using this apparatus, therefore, is to obtain a uniform and maximum desirable tension on the yarn which results in a uniform twist between various bob- "bins of the same device and also between various points on the same thread. In this way yarns or threads of uniform characteristics, such as their crepeing properties, compactness, di-' ameter, etc., are formed. In the finished fabric formed from such yarns, therefore, the result is a more uniform hand, a more even crepe, if the threads were designed for crepe fabric, and also freedom from warp and weft bars.

By employing this invention the highest possible twisting emciency of a given machine may be had owing to the fact that, while the tension of the yarn can be maintained uniformly high, extremes of tension likely. to break the yarn are not present. For instance, with the use of ordinary fiyers it is possible to increase the average tension to a point desired by using a heavier flyer but this is limited by the fact that it is possible to over-step the mark and obtain a low twisting efllciency'because of the breaking down of ends of yarn under the influence of the extremely high tensions occurring as the twisting bobbins run empty. By employing my invention, however, this cause of the breaking of yarns or filaments is removed.

In accordance with my invention I apply twist to yarn by an upward twisting method employing a flyer and I provide means whereby a uniform tension is maintained on the yarn, which uniform tension is automatically obtained by changing the direction of the thread leaving the flyer, by changing the amount of friction caused between the thread and metallic bars and guides and by an adjustment of a moment of force acting upon the thread as it travels from the supply bobbin to the take-up bobbin. In accordance with my invention, I also construct a device which comprises a lever arm that is adapted to move in response to the actual tension on the yarn or thread, thereby changing the direction of travel of the yarn or thread, its length of contact with guide elements and the applied pull exerted by a weight on the yarn.

While this invention is applicable to the twisting of yarns of all kinds, whether made of continuous filaments or short lengths of filaments or made of natural fibres or of artificial filaments, it is particularly applicable for the twisting of yarns of fine denier and/or low tenacity made of artificial filaments particularly those of substantially continuous lengths. The artificial filaments may be formed of any organic derivatives of cellulose such as organic esters of cellulose and cellulose ethers. Examples of organic esters of cellulose are cellulose acetate, cellulose for-4 mate, cellulose propionate and cellulose butyrate, while examples of cellulose ethers are methyl cellulose, ethyl celluloseand benzyl cellulose. This invention is also useful for the twisting of yarns made of reconstituted cellulose such as made by the viscose, cuprammonium or Chardonnet process. Composite yarns of various kinds, as for example, yarns combining cellulose acetate or other synthetic yarn and natural silk or other natural fibres such as wool, cotton, etc. or yarn combining two or more synthetic fibres maybe twisted by my process. l

The operation of this device, both in the case of ordinary flyer twisting and super or crepe twisting for crepe yarn, depends on the use and coordination of at least two principles. The first principle, and perhaps the most important, is the fact that, when in ordinary flyer twisting, the vertical thread proceeding from the top of the flyer'toward the center eye above is deflected to one side so as to make an angle with the vertical, the tension on the thread becomes reduced. The second principle is the fact that when the thread passes over a thread guide or any such device in such a way as to describe an. angle with itself, tension is put on the thread. This tension will increase if the angle formed by the contact of the guide with the thread is decreased and conversely tension will decrease when the angle is increased. For instance, if the thread passes over one, two, or more guides, the tension on the yarn can be materially altered by altering the position of the guides in relation one to another in such a way that the angle of contact and length of contact of the thread with the particular guides involved is increased or decreased. In the method and device herein described these two principles act cooperatively in accordance with requirements in such a way that though, as twisting conditions vary, the tension of the yarn may change to a very great extent yet, through the compensating eil'ect of these two cooperating principles automatically applied, the tension is maintained approximately constant.

In the particular device herein described and forming a part of this invention, it will be noted that the two coordinating factors of direction of travel of the yarn and angle and distance of contact of yarn with guide members are automatically changed in coordination with the change in position of a lever arm carrying an adjustable weight, which lever regulates itself in response to the variations of tension imparted to the thread by the action of the flyer under changing circumstances. The weight may be adjusted to give any desired degree of tension upon the yarns by moving same out or in upon the lever arm. By positioning the lever andad- Justing the same, a lever action is formed which regulates the two factors stated above differentially in proportion to a moment of force which varies according to the position of the lever arm as the same moves from a horizontal to a vertical position, thus shortening or lengthening the distance between the mass of weight and a vertical line through the fulcrum of the lever arm.

As an aid to describing this invention, the same will be described with reference to the device shown in the drawing which also forms a part of this invention. In the device shown in the drawing there may be provided a vertical spindle i adapted to be rotated in any suitable manner. The spindle i is adapted to support a bobbin 2 containing the supply of yarn. A collar 3 adapted to fit over the spindle I and be in rotative relationship thereto may be provided for supporting the flyer 4 that may be of any suitable type, for instance, consisting of guide eyes 5 and 6 and a balancing arm 1. The spindle may ride in suitable bearings attached to the main frame of the device which main frame is not shown in detail on the drawing. While a Figure 8 flyer is shown on the drawing, this invention is applicable to the use of other flyers, such as the Figure f" flyer, the two arms straight flyer, or the universal flyer.

. Above each vertical spindle on the device, where a bank of spindles is used, there may be provided a roller 8 that may be suitably covered with a friction material such as cork, felt or the like, upon which a take-up spool 9 is adapted to ride and-.be rotated thereby due to the friction between the surfacing material on the roller 8 and the core or the yarn wound on the core ofthe take-up spool 8. In place of the spool 9, any

type of take-up package may be formed, for instance, a cheese, cone, etc. Also mounted on the main frame may be a, reciprocating bar l0 suitably driven by a source of power coordinated with the power employed for rotating the vertical spindle.

v Mounted on the reciprocating bar in in registry with or corresponding to each spool 9, may be a guide member I I. Guide member ll may be made of any suitable material such as metal, porcelain or composition and the same may 75 be fastened in any suitable manner to the reciprocating bar I0. Furthermore, the guide memher I I'ma'y be of any suitable shape or construction for guiding the yarn on tov the take-up spool 9. The speed of rotation of the take-up spool 9 On the main frame there may be provided,

above each vertical spindle, a stationary member I2. Suitably fastened to the stationary member I2 at a point to one side of a vertical line forming an extension of the vertical spindle, may be a rod or axle IS. The rod or axle I3 may be fastened to the stationary member l2 in any suitable manner as by the lug I4 passing through the stationary member. The lug I4 may be operated in a slot in the stationary member I2 for adjustment lengthwise of the stationary member I2 and be held in any set position by means of washers and nut I5. The outer end of the rod or axle I3 may be bent to form a pig-tail guide IS. The rod or axle I3 is rotatably mounted in the lug M. Mounted on the rod or axle I8 and free to revolve upon it may be a collar I 1 from which collar there may extend two arms, one arm I8 adapted to support a weight I9 adjustable along the length thereof and the other arm 20 that terminates in a hook 2i adapted to support and/or act as a guide for the yarn 22 that is being twisted.

In operation, a supply bobbin containing yarn to be twisted is placed on the rotating spindle i and above it, on the spindle, is mounted the flyer 4, which flyer may be prevented from coming off the spindle by the collar or mill-nuns. The yarn 22 is threaded through the eyes 5 and 6 In the flyer over the hook 2i then through the stationary pig-tail guide I6, passing finallyover the reciprocating guide I I onto the take-up package or spool 9. The spindle I is rotated at a relatively high speed while the take-up package is rotated ata relatively slow speed, the differential between the 'two regulating the amount of twist inserted in the yarn.

When the supply package is full, as shown in solid lines on the drawing, the tension applied to the yarn by the flyer is at a minimum, at which time the weight I9 is adjusted on the lever arm I8 such that the tension of the yarn is no more than sufiicient to hold the lever in substantially the position shownin solid lines in the drawing. As the supply bobbin becomes empty, the yarn tension applied by the flyer will tend to increase and the arm I8 will tend to take the position shown in dotted lines on the drawing This gradually increasing tension will exert a corresponding gradually increasing pull downward on the hook 2I, which increasing pull will rotate the movable member supporting the hook, swinging the hook downwards and to the right of its former position, as seen from the front of the apparatus. The lowering of the hook 2| will change the angle at which the yarn leaves the flyer and in so doing will tend to counteract the increasing tension which would normally be applied to the yarn by the flyer as the result of the decreasing diameter of the supply package. Further, as the hook 2i swings in a counter-clockwise direction the yarn makes a less sharp bend about the hook 2| and the guide I! and in that manner further tends to counteract the increasing flyer tension. Furthermore, it will be noticed that as the hook moves downward and the weight I9 is rotated in a counterclockwise direction, the moment of force exerted by the weight upon hook 2| is reduced. By the coordination of these three principles, the tension on the yarn, which would otherwise increase In accordance with the decrease of the external diameter of the yarn package, is automatically maintained approximately uniform by the compensating effect of said three principles caused by the position of the yarn leaving the supply bobbin such that during the entire run the tension on the yarn is uniform. In a similar manner the working of these same three prinflyer tensions that normally accompany the unwinding of the yarn from the supply bobbin as theunwindingend of yarn traverses the length of the bobbin from top to bottom and back again.

. ciples automatically compensates for the varying It is to be understood that the device shown I may be considered a complete unit or a mere segment of a device, for instance, a bank containing any number of vertical spindles may be provided with a corresponding tensioning device and takeup device for each vertical spindle, the entire bank of spindles and take-up devices being operated from a single source of power. Further, devices may be formed in which there are multiple banksof spindles on one or both sides of said devices as is customary in the twisting devices now in general use. It is'to be understood also, that in place of moving the lug It in a slot in the member I? the whole member I2 may be made adjustable, or both may be made adjustable.

It is to be understood'that the foregoing detailed description and drawing are given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my Invention, what I desire to secure by Letters Patent is:

1. Apparatus for twisting yam comprising a rotating vertical spindle adapted to support a yarn package from which the yarn is drawn on, a; winding device adapted to wind the yarn whereby twist is imparted to the yarn, a flyer for assisting the twisting of the yarn, a guide for the yarn between the. winding device and said flyer and means including an arm pivoted at said guide for guiding the path of the yarn between the flyer and said guide adapted torespond to the actual tension on the yarn for diverting the yarn between said flyer and said winding device from a line passing through the axis of the yarn package.

2. Apparatus for twisting yarn, comprising ato rotate said take-up package at a constant rate, a flyer adapted to assist in applying twist to the yarn and means for controlling the tension on the yarn being wound on the take-up package, said tension controlling means comprising a guide for the yarn positioned between the take-up package and the flyer and means adapted to respond to the actual tension on the yarn for diverting the yarn between said flyer and said guide from a line passing through the axis of the yarn supply package.

3. Apparatus for twisting yarn, comprising a rotating vertical spindle adapted to support. a

yarn supply package, a take-up package, means to rotate said take-up package at a constant rate, a flyer adapted to assist in applying twist to the yarn and means for controlling the tension on the yarn being wound on the take-up package, said tension controlling means coming twist to the Yarn and means for controlling the tension on the yarn being wound on the take-up package, said tension controlling means comprising a guide for the yarn positioned between the take-up package and the fiyer and means, including a counter-balanced pivoted arm, for diverting the yarn between said flyer and said guide from a line passing through the axis of the yarn supply package, said pivoted arm being adapted to rotate in response to the 10 actual tension on the yarn.

LESLIE J. ODOWD. 

